1. Field of the Invention
The present invention generally relates to electrical signal reproducing and recording apparatus and, more particularly, to a play/record switching circuit for such apparatus of the type having inputs for a plurality of source data signals and a microphone data signal, and a tape head arrangement for generating a tape head reproducing signal and for receiving one of the data signals to be recorded.
2. Description of the Prior Art
It has been proposed to employ a play/record switching circuit in an electrical signal reproducing and recording apparatus such as the receiver section of a tape recorder. This proposed switching circuit is actuated by a conventional play-record button to simultaneously perform many different functions.
For example, depending upon whether the play or the record mode is selected by the button, the reproducing/recording tape head is disabled or enabled relative to the appropriate electronic amplifier components, the bias oscillator and bias trap are disabled or enabled relative to the erase head and the reproducing/recording tape head, the record indicator light is disabled or enabled, the source data signals are disabled or enabled relative to the appropriate electronic amplifier components, the microphone data signal is disabled or enabled relative to the appropriate electronic amplifier components, the appropriate equalizer networks for the microphone and tape head reproducing and recording amplifiers are disabled or enabled, the ground connection across the reproducing/recording tape head is reversed, and the program indicator lights for an 8 track deck for the microphone data signal or the source data signals are actuated or deactuated, just to mention a few possible functions for the known switching circuit.
This proposed switching circuit effects the above-described functions by a very complex multi-pole or multi-section rotary mechanical switch having a plurality of wafer sections. The known mechanical multi-part switch is of large size and has a complicated construction due in part to the many functions which the switching circuit is called on to perform. The multi-part switch requires a multitude of wires extending from the various wafer sections of the switch to the various components to be disabled or enabled. This means in turn that a multitude of soldering processes are necessary to assemble the switching circuit.
Although the known multi-part switches are generally adequate for their intended purposes, they have not proven to be altogether practical in operation. Many man-hours are needed to assemble the complex switch. Mechanical failure is prevalent because the many solder connections and attendant oxidation with time increase the failure rate and decrease the overall reliability of the switching circuit. The control circuitry inter-connection with the switch is complicated and requires expert technical personnel. Moreover, due to intercoupling between the multitude of wires, an undesirably high noise level is obtained. Furthermore, it is difficult to reliably actuate the apparatus with a remote control device due to the multitude of mechanical switch sections within the known switching circuit.